Technology Papers
A brief abstract of the paper is provided under the title. Should you wish more, simply clicking on the title will open the full paper in a new window.
A brief abstract of the paper is provided under the title. Should you wish more, simply clicking on the title will open the full paper in a new window.
Low cost Dynamic Drive Scheme and Reflective Bistable Cholesteric Liquid Crystal Displays
Bistable reflective cholesteric liquid crystal displays have significant optical and power consumption advantages over conventional liquid crystal displays. In order that they become commercially viable, their drive electronics must be inexpensive and compatible with standard information device electronics. We have developed a simplified dynamic drive scheme and the circuitry necessary to implement it using off-the shelf components at a cost of less than $0.03 per driver output.
Polymer-Stabilized Bistable Black-White Cholesteric Reflective Display
We report a polymer stabilized bitable black-white cholesteric reflective display, in which a small amount of the polymer network is dispersed in the cholesteric liquid crystal. When the material is in the planar texture, because of the presence of the polymer network, the orientation of the helical axes of the material has a wide distribution, and thus the material reflects white light under room light condition. When the mixture is in the focal conic texture, it has a black appearance because the incident light is diffracted or scattered in forward directions and absorbed by an absorption layer on the bottom plate.
Multiple Color High Resolution Reflective Cholesteric Liquid Crystal Displays
The first multiple color and black on white surface stabilized reflective cholesteric liquid crystal display is demonstrated. A high resolution, double, stack, 1/8 VGA, 100 dpi, prototype shows four vivid colors without parallax.
High-Speed Dynamic Drive Scheme for Bistable Reflective Cholesteric Display
We designed a drive scheme for a bitable reflective cholesteric displays which is composed of five phases: preparation, post-preparation, selection, post-selection, and evolution. The state of the material after addressing depends only on the voltage in the selection phase which is around 50 us long. The voltages in other phases are fixed at appropriate values and the drive waveform is implemented using a pipeline algorithm. Using this drive scheme, we are able to update a 1000 line bistable cholesteric display in approximately 0.05 seconds.
Compatibility of Birefringent Plastic Substrates with High Resolution Reflective Cholesteric Liquid Crystal Displays
We report the highest resolution surface stabilized reflective cholesteric liquid crystal display (Ch-LCDs) fabricated using plastic substrates. Displays with resolutions of 100 and 126 dpi on birefringent polyester (PET) and polycarbonate are discussed. We show that these displays have similar electro-optical and optical characteristics when compared to displays constructed using glass.
Freedericksz Transition Measurements on Polymer-Stabilized Liquid Crystals
Electric-field Freedericksz transition experiments were performed on homogeneous nematic sample of pentylcyanobiphenyl in which an anisotropic cross-linked polymeric network was formed. The studies geometry yields the splay elastic constant from the threshold voltage, Vc.VC; those in which the network was formed with the field ON, I.e. in the homeotropic alignment, showed a decrease in Vc. These observations are interpreted in terms of a model which assumes that the nematic elasticity, as well as on the Frank elastic constant. From this relationship, values of network elastic modules can be estimated.
We have measure both of the elect optical and the Raman characteristics of polymer-stabilized cholesteric texture (PSCT) films fabricated with various polymer concentrations. Some correlations between these two characteristics were found. This indicates the Raman experiment could provide us another technique to analyze the PSCT films.